Using Guttman's mapping sentences and Many Facet Rasch Measurement Theory to develop an instrument that examines the grading philosophies of teachers

Abstract

This study presents an approach to questionnaire design within educational research based on Guttman's mapping sentences (Guttman, 1977) and Many-Facet Rasch Measurement Theory (Linacre, 1994). The primary purpose of this study was to illustrate how Guttman's mapping sentences can be used to develop an instrument that explores the grading philosophies of teachers. A secondary purpose was to clarify teacher grading philosophies (i.e., severity or leniency) as a measurement construct. We designed a 54-item questionnaire in which each item represented a unique combination of student characteristics, i.e., varying levels of classroom achievement, ability, behavior, and effort. The grades assigned by the teachers to the scenarios were analyzed using the FACETS (Linacre, 2007) computer program. The results of the analyses suggest that the grading philosophies of teachers represent a unidimensional construct which is influenced, to varying extents, by the classroom achievement (primarily), behavior, and effort of students; whereas the measurement value added by the inclusion of the ability facet is uncertain.